It would be better if you mentioned your age also.As you have undergone MVR twice,so you are really concerned about the pain that radiates to the back.
The pain you are describing does not look like cardiac in origin, although you need to have further tests to exclude this like ECG, Chest X-ray or echo.
Cardiac pain that happens due to some problem with the valve or arteries usually goes to left arm and associated with Shortness of breath
, apprehension, sweating or palpitations. it does not change on changing position or goes into hips.
I personally feel that this pain is muscular or can be due to some medication you are on. (like lasix
, spiromide, digoxin
But still if you have symptoms you can go go check your doctor for some tests.
Hope this answer would have helpe you in making things clear
Dr. Atif Nazir